add gmail app password example

[softprops]

this adds a new example to help illustrate a reproducible case for https://github.com/jonhoo/rust-imap/issues/106 and an alternative to oauth2 tokens for users of this crate in the future

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This change is 

[codecov[bot]]

Codecov Report

Merging #107 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #107   +/-   ##
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  Coverage   78.74%   78.74%           
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  Files          11       11           
  Lines        1167     1167           
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  Hits          919      919           
  Misses        248      248

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[codecov[bot]]

Codecov Report

Merging #107 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #107   +/-   ##
=======================================
  Coverage   78.74%   78.74%           
=======================================
  Files          11       11           
  Lines        1167     1167           
=======================================
  Hits          919      919           
  Misses        248      248

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update ead7d21...8a43957. Read the comment docs.

[jonhoo]

Actually, on second thought, this is super similar to the basic.rs example. I think maybe we just want to add a comment about app passwords in basic.rs. Maybe even rename it to gmail.rs + change the server address so it works "out of the box"?

[jonhoo]

@softprops what do you think of my comment above?

[softprops]

Im going to go ahead and close this, I was able to unblock myself to testing with another gmail account. feel free to close this

[jonhoo]

Oh, that's too bad. What problem did you run into?

[softprops]

This problem https://github.com/jonhoo/rust-imap/issues/106, something was up with my google account that caused this library to be unable to parse the imap responses. I timeboxed investigating that then ended up just using another gmail account.

[jonhoo]

Ohh, I remember now. That's too bad — your updated example would be a good addition :)